U.S. patent application number 13/979732 was filed with the patent office on 2013-11-14 for shield conductor.
This patent application is currently assigned to AUTONETWORKS TECHNOLOGIES, LTD.. The applicant listed for this patent is Naoki Aoyama, Sonoda Fujio, Yasushi Itani, Katsutoshi Izawa, Masanori Kuwahara, Yoshinori Sugimoto. Invention is credited to Naoki Aoyama, Sonoda Fujio, Yasushi Itani, Katsutoshi Izawa, Masanori Kuwahara, Yoshinori Sugimoto.
Application Number | 20130299234 13/979732 |
Document ID | / |
Family ID | 46757862 |
Filed Date | 2013-11-14 |
United States Patent
Application |
20130299234 |
Kind Code |
A1 |
Izawa; Katsutoshi ; et
al. |
November 14, 2013 |
SHIELD CONDUCTOR
Abstract
A shield conductor includes: an electrical wire; a tubular
shield member that encloses the electrical wire and is configured
such that an end portion of a pipe made of metal is fit to an end
portion of a tubular accordion member made of metal; a swage ring
that is attached at a portion where the end portion of the pipe is
fit to the end portion of the tubular accordion member, and
constricts the end portion of the pipe and the end portion of the
tubular accordion member from outside; a conductor ring that is
arranged between the pipe and the tubular accordion member, has an
inner circumferential face that faces the pipe and an outer
circumferential face that faces the tubular accordion member, and
has electrical conductivity; and a plurality of
protrusion/recession portions formed on the inner circumferential
face and the outer circumferential face.
Inventors: |
Izawa; Katsutoshi; (Mie,
JP) ; Kuwahara; Masanori; (Mie, JP) ; Fujio;
Sonoda; (Mie, JP) ; Itani; Yasushi; (Mie,
JP) ; Sugimoto; Yoshinori; (Mie, JP) ; Aoyama;
Naoki; (Mie, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Izawa; Katsutoshi
Kuwahara; Masanori
Fujio; Sonoda
Itani; Yasushi
Sugimoto; Yoshinori
Aoyama; Naoki |
Mie
Mie
Mie
Mie
Mie
Mie |
|
JP
JP
JP
JP
JP
JP |
|
|
Assignee: |
AUTONETWORKS TECHNOLOGIES,
LTD.
Mie
JP
SUMITOMO ELECTRIC INDUSTRIES, LTD.
Osaka
JP
SUMITOMO WIRING SYSTEMS, LTD.
Mie
JP
|
Family ID: |
46757862 |
Appl. No.: |
13/979732 |
Filed: |
February 23, 2012 |
PCT Filed: |
February 23, 2012 |
PCT NO: |
PCT/JP2012/054362 |
371 Date: |
July 15, 2013 |
Current U.S.
Class: |
174/70R |
Current CPC
Class: |
H02G 3/06 20130101; H02G
3/0468 20130101; H02G 3/0481 20130101; H02G 3/0406 20130101 |
Class at
Publication: |
174/70.R |
International
Class: |
H02G 3/04 20060101
H02G003/04 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 28, 2011 |
JP |
2011-041712 |
Claims
1. A shield conductor comprising: an electrical wire; a tubular
shield member that encloses the electrical wire and is configured
such that an end portion of a pipe made of metal is fit to an end
portion of a tubular accordion member made of metal; a constricting
member that is attached at a portion where the end portion of the
pipe is fit to the end portion of the tubular accordion member, and
constricts the end portion of the pipe and the end portion of the
tubular accordion member from outside; a conductor ring that is
arranged between the pipe and the tubular accordion member, has an
inner circumferential face that faces the pipe and an outer
circumferential face that faces the tubular accordion member, and
has electrical conductivity; and a plurality of
protrusion/recession portions formed on the inner circumferential
face and the outer circumferential face.
2. The shield conductor according to claim 1, wherein the conductor
ring is shaped as a C-ring obtained by bending a metal plate so as
to be shaped as a circular arc.
3. The shield conductor according to claim 1, wherein the plurality
of protrusion/recession portions are formed by a plurality of
grooves that form a lattice.
4. The shield conductor according to claim 1, wherein the tubular
accordion member includes a slit cut from an open end of the
tubular accordion member in a portion that is fit to the outside of
the pipe.
5. The shield conductor according to claim 1, wherein a cylindrical
connection portion that conforms to the outer circumferential face
of the conductor ring is formed in a portion of the tubular
accordion member that is fit to the outside of the pipe.
6. The shield conductor according to claim 5, wherein the tubular
accordion member is provided with a seal tube portion that forms an
annular gap with the pipe by expanding the cylindrical connection
portion with a step in a portion that is continuous with the
cylindrical connection portion, and a seal ring is arranged between
the pipe and the seal tube portion.
Description
TECHNICAL FIELD
[0001] The present invention relates to a shield conductor.
BACKGROUND ART
[0002] Conventionally, in vehicles such as hybrid automobiles and
electric automobiles, a shield conductor having a shield function
is used when interconnecting devices such as inverters and motors,
and a known example of a shield conductor is disclosed in Patent
Document 1. This shield conductor includes multiple electrical
wires and a tubular shield means that encloses all of the
electrical wires, and the shield means is configured such that a
connection pipe, a tubular braided member, and a shield shell are
connected to both ends of a metal pipe in the stated order. When
the shield shells located at the two end portions of the shield
means are fixed to shield cases in which devices such as an
inverter are accommodated, the entire circumference of the
electrical wires connecting the devices can be enclosed by the
shield shells.
CITATION LIST
Patent Documents
[0003] Patent Document 1: JP 3909763B
SUMMARY OF INVENTION
Technical Problem
[0004] However, according to this configuration, the tubular
braided member is obtained by braiding thin metal wires into a
mesh, which makes it easy for it to get caught on a peripheral
member during attachment work and the like, thus reducing work
efficiency, and there is also the risk of a reduction in shield
performance if the tubular braided member is ripped.
[0005] The present invention was achieved in light of the
above-described situation, and an object thereof is to provide a
shield conductor that is superior in terms of the ease of
arrangement work and can improve shield performance.
Solution to Problem
[0006] One aspect of the present invention is a shield conductor
including: an electrical wire; a tubular shield member that
encloses the electrical wire and is configured such that an end
portion of a pipe made of metal is fit to an end portion of a
tubular accordion member made of metal; a constricting member that
is attached at a portion where the end portion of the pipe is fit
to the end portion of the tubular accordion member, and constricts
the end portion of the pipe and the end portion of the tubular
accordion member from outside; a conductor ring that is arranged
between the pipe and the tubular accordion member, has an inner
circumferential face that faces the pipe and an outer
circumferential face that faces the tubular accordion member, and
has electrical conductivity; and a plurality of
protrusion/recession portions formed on the inner circumferential
face and the outer circumferential face.
[0007] According to this configuration, superior ease of
arrangement work and improved shield performance can be achieved in
comparison with the case where braided wire such as a tubular
braided member, which is obtained by braiding thin metal wires into
a mesh, is integrated in an end portion of a metal pipe, for
example, as in conventional technology.
[0008] Specifically, if braided wire having superior flexibility,
for example, is used in the portion of the shield member where the
pipe and a device or the like are connected, the thin metal wires
easily become frayed at the end portion of the braided wire. For
this reason, the frayed thin metal wires easily become caught on a
peripheral member during attachment work and the like, and there is
the risk of a reduction in workability. Also, braided wire
configured from thin metal wires easily rips, and there is the risk
of a reduction in shield performance if it rips.
[0009] In contrast to this, according to the present invention,
instead of braided wire, the tubular accordion member is connected
to the pipe. Due to using a member obtained by working a metal foil
or other thinly drawn out metal into an accordion-like shape as the
tubular accordion member, for example, the end portions thereof do
not fray. As a result, the tubular accordion member does not become
caught on a peripheral member during attachment work or the like,
thereby making it possible to have superior ease of arrangement
work.
[0010] Additionally, the tubular accordion member made of a metal
foil or the like is sturdier and less easily ripped than braided
wire. In other words, due to having superior durability, it is
possible to reliably prevent interference between the inserted
electrical wires and foreign objects, and protect them from other
peripheral members. Furthermore, due to using the tubular accordion
member that has superior durability, it is possible to achieve
shield performance compliant with the metal pipe, thereby enabling
an improvement in the shield performance as a shield conductor.
[0011] Also, the pipe and the tubular accordion member are
electrically connected via the conductor ring that is arranged
between the pipe and the tubular accordion member. Also, multiple
protrusion/recession portions are formed on the inner
circumferential face of the conductor ring that faces the pipe and
the outer circumferential face of the conductor ring that faces the
tubular accordion member. Accordingly, even if an oxide layer is
formed on the outer surface of the pipe or the inner surface of the
tubular accordion member, the oxide layer will be broken when
pressed by the protrusion/recession portions, thus establishing a
favorable electrical connection state between the pipe and the
conductor ring and between the conductor ring and the tubular
accordion member, and improving shield performance and the
reliability of the connection with the pipe and the tubular
accordion member.
[0012] Specifically, first, if multiple protrusion/recession
portions are provided on the inner circumferential face of the
conductor ring that faces the pipe, the protrusion/recession
portions dig into the pipe when constricted from the outside by the
constricting member, and even if an oxide film is formed on the
outer surface of the pipe, the oxide film will be broken, and the
electrical connection state between the conductor ring and the pipe
will be favorable. Also, if multiple protrusion/recession portions
are also provided on the outer circumferential face of the
conductor ring that faces the tubular accordion member, the
protrusion/recession portions dig into the inner surface of the
tubular accordion member when constricted from the outside by the
constricting member, and the electrical connection state between
the conductor ring and the tubular accordion member will similarly
be favorable. As a result, it is possible to improve shield
performance with respect to the electrical wires inserted into the
pipe.
[0013] The following modes are preferable as modes for implementing
the present invention.
[0014] It is desirable that the conductor ring is shaped as a
C-ring obtained by bending a metal plate so as to be shaped as a
circular arc. In order for the pipe and the tubular accordion
member to be constricted by the constricting member from the
outside with the conductor ring therebetween, first, the conductor
ring, which is held on the pipe and covered by the tubular
accordion member, needs to be constricted from directly above with
the constricting member. At this time, if the conductor ring is
shaped as a C-ring, it is possible to appropriately change the
position of the conductor ring in conformity with the constricting
member and the tubular accordion member even after it is held on
the pipe. In other words, if the conductor ring is shaped as an
O-ring, it needs to be pressed against at least the pipe due to
being a conductor ring having protrusion/recession portions that
dig into the pipe and the tubular accordion member, and therefore
it is difficult to conceive of the position of the conductor ring
being able to be changed after being held on the pipe. In contrast,
if the conductor ring is shaped as a C-ring, it is possible to
reduce the diameter of the conductor ring at the same time as
constriction with the constricting member, and to cause the
protrusion/recession portions to dig into the pipe and the tubular
accordion member. Accordingly, if the conductor ring is shaped as a
C-ring, and the inner diameter is set to a dimension that is
sufficiently larger than the outer diameter of the pipe so as to
allow its position to be changed, the position can be changed even
after the conductor ring is held on the pipe, thus achieving
superior workability.
[0015] It is desirable that the plurality of protrusion/recession
portions are formed by a plurality of grooves that form a lattice.
This configuration enables forming the plurality of
protrusion/recession portion at the same time using knurling work,
for example, and thus is superior in terms of formability.
[0016] Also, forming a plurality of grooves that form a lattice is,
in other words, the formation of multiple rectangular protrusions,
and therefore the multiple protrusions dig into the pipe and the
tubular accordion member that face the conductor ring, thus making
it possible to increase the fixing force of fixation to the pipe
and the tubular accordion member. Additionally, due to the
protrusions digging into the pipe and the tubular accordion member,
it is possible to secure a large surface area of contact that the
conductor ring has with the pipe and the tubular accordion member,
thus enabling suppressing contact resistance and further securing
sufficient connection reliability.
[0017] The tubular accordion member may be provided with a slit cut
from an open end of the tubular accordion member in a portion that
is fit to the outside of the pipe. A drawback of the tubular
accordion member is that it less readily undergoes deformation than
braided wire. In contrast to this, a slit is provided in the
portion that is fit to the outside of the pipe, thus enabling the
diameter to be easily reduced to conform to the outer diameter of
the pipe even when constricting it from the outside with the
constricting member. This makes it possible to achieve superior
ease of attachment work.
[0018] A cylindrical connection portion that conforms to the outer
circumferential face of the conductor ring may be formed in a
portion of the tubular accordion member that is fit to the outside
of the pipe. According to this configuration, the portion of the
tubular accordion member that is fit to the outside of the pipe is
given a cylindrical shape in advance, thus having superior
workability compared to the case of having an accordion-like shape.
Specifically, when the pipe and the tubular accordion member are
constricted by the constricting member with the conductor ring
therebetween, if the site of the tubular accordion member that
directly comes into contact with the conductor ring is the
cylindrical connection portion that conforms to the outer
circumferential face of the conductor ring, there will be no
positional displacement of the tubular accordion member relative to
the conductor ring before and after constriction. This enables
reliably constricting the tubular accordion member to the pipe with
the conductor ring therebetween, and enables achieving superior
workability. Also, by giving the constricting portion a shape that
conforms to the outer circumferential face of the conductor ring,
more surface area of contact with the conductor ring is secured,
thus enabling suppressing contact resistance and achieving
sufficient electrical connection.
[0019] The tubular accordion member may be provided with a seal
tube portion that forms an annular gap with the pipe by expanding
the cylindrical connection portion with a step in a portion that is
continuous with the cylindrical connection portion, and a seal ring
may be arranged between the pipe and the seal tube portion. This
configuration enables preventing the intrusion of water, entrance
of foreign objects, and the like from the outside via the portion
where the pipe and the tubular accordion member are
constricted.
Advantageous Effects of Invention
[0020] According to the present invention, it is possible to
provide a shield conductor that is superior in terms of the ease of
arrangement work and can improve shield performance.
BRIEF DESCRIPTION OF DRAWINGS
[0021] FIG. 1 is a side view of a connection portion for connecting
a tubular accordion member and a pipe of a shield conductor
according to Embodiment 1 of the present invention.
[0022] FIG. 2 is a lateral cross-sectional view of the same.
[0023] FIG. 3 is a cross-sectional view taken along A-A in FIG.
1.
[0024] FIG. 4 is a perspective view of a conductor ring.
[0025] FIG. 5 is a side view of connection portion for connecting a
tubular accordion member and a pipe of a shield conductor according
to Variation 1 of Embodiment 1.
[0026] FIG. 6 is a perspective view of a conductor ring according
to Embodiment 2.
[0027] FIG. 7 is a perspective view of a conductor ring according
to Embodiment 3.
DESCRIPTION OF EMBODIMENTS
Embodiment 1
[0028] The following describes Embodiment 1 of the present
invention with reference to FIGS. 1 to 4.
[0029] A shield conductor 10 of the present embodiment is arranged
between devices such as a battery, an inverter, and a motor (not
shown) that configure the power source for traveling in a vehicle
such as an electric automobile. The shield conductor 10 is
configured so as to include two electrical wires 11 when arranged
between a battery and an inverter, and include three electrical
wires 11 when arranged between an inverter and a motor. The present
embodiment describes a shield conductor 10 that is arranged between
an inverter and a motor under the floor of a vehicle and includes
three electrical wires 11.
[0030] As shown in FIGS. 1 to 3, the shield conductor 10 is
configured by three electrical wires 11 and a shield member 20 that
has a shield function and into which the three electrical wires 11
are inserted. The shield member 20 is configured so as to include a
pipe 21 that is arranged under the floor of the vehicle, and a
tubular accordion member 30. The tubular accordion member 30 has
superior flexibility, is connected to each end portion of the pipe
21 in a conductible manner, and is for connecting the pipe 20 to
devices.
[0031] Each electrical wire 11 is a round (having a circular cross
section) covered electrical wire, and as shown in FIG. 3, is
configured from a core wire 12 and an insulating sheath 13
(insulation layer) that encompasses the core wire 12. The core wire
12 is made of copper or a copper alloy, and is a single core wire
or a twisted wire obtained by twisting together multiple metal
wires. A terminal fixture (not shown) is connected to each end of
the three electrical wires 11, and the electrical wires 11 are
drawn out from the pipe 21 and the tubular accordion member 30 that
is continuous with the pipe 21, for connection to a terminal on the
device side.
[0032] The pipe 21 is made of metal (e.g., aluminum or an aluminum
alloy), is cylindrical, and has an inner diameter that allows the
insertion of the three electrical wires 11. Specifically, the pipe
21 has a cross-sectional shape that is a true circle as shown in
FIG. 3, and an outer circumferential face 21A and an inner
circumferential face 21B are shaped as concentric circles, that is
to say, the thickness of the pipe 21 is constant over the entire
circumference. Also, the outer circumferential face 21A of the pipe
21 is a smooth arc-shaped surface. As shown in FIG. 2, a guiding
inclined face 21C inclined such that the diameter decreases in the
rearward direction from the outer circumferential face 21A is
formed in the edge portion of the opening of the pipe 21. The
guiding inclined face 21C allows the pipe 21 to be easily inserted
into an O-ring 22 (corresponding to a seal ring) that is fitted
around the pipe 21, and into the tubular accordion member 30 that
encompasses the O-ring 22. Besides the shield function, the pipe 21
configured in this way also has a function of protecting the
electrical wires 11, and is suited to the case of being arranged
under the floor of a vehicle, where there is the risk of the
electrical wires 11 being damaged due to being hit by flying rocks
or the like.
[0033] The end portion of the pipe 21 is fitted into the end
portion of the tubular accordion member 30. Specifically, the end
portion of the pipe 21 is inserted into the tubular accordion
member 30 through an open end 31 thereof. In other words, the end
portion of the tubular accordion member 30 is arranged so as to be
outward of the end portion of the pipe 21 with respect to the
diameter direction of the pipe 21. Furthermore, a swage ring 40
(corresponding to a constricting member) is swaged from the outside
at the portion where the end portion of the pipe 21 and the end
portion of the tubular accordion member 30 are fitted together. The
pipe 21 and the tubular accordion member 30 are thus electrically
connected.
[0034] The tubular accordion member 30 is made of metal (e.g.,
copper or a copper alloy, which are superior in terms of
flexibility) likewise to the pipe 20, and is formed into a
thin-film accordion-like shape. As shown in FIGS. 1 to 3, the
tubular accordion member 30 is substantially cylindrical overall,
and the portion thereof formed into an accordion-like shape is a
main portion 32. As shown in FIG. 2, between the main portion 32
and the open end 31, a seal tube portion 33 and a cylindrical
connection portion 34 are provided in the stated order from the
main portion 32 side. As will be described in detail later, the
seal tube portion 33 corresponds to a site where it encompasses the
circumference of the O-ring 22, which is fitted onto the pipe 21,
from the outside in close contact, and the cylindrical connection
portion 34 corresponds to a site where the pipe 21 is swaged from
the outside by the swage ring 50 via a conductor ring 40 held on
the pipe 21.
[0035] Convex portions 32A of the main portion 32 that expand
outward and extend in the circumference direction are arranged in
parallel with a predetermined regular pitch along the axial
direction. Portions between the convex portions 32A are concave
portions 32B that bulge inward, and the convex portions 32A and the
concave portions 32B are arranged alternatingly so as to form an
accordion-like shape, thus achieving flexibility so as to be able
to flexibly follow the path along which the electrical wires 11 are
to be arranged.
[0036] The seal tube portion 33 is formed so as to increase in
diameter from the cylindrical connection portion 34 with a step,
and forms an annular gap equal to the thickness of the O-ring 22
with the outer circumferential face 21A of the pipe 21. As shown in
FIG. 2, this gap can accommodate the O-ring 22 when it is fitted
around the outer circumferential face 21A of the pipe 21. The
O-ring 22 is configured by an elastic body such as rubber, and
forms a water-tight seal between the inner circumferential face of
the seal tube portion 33 and the outer circumferential face 21A of
the pipe 21 due to being in close contact with them.
[0037] The cylindrical connection portion 34 is formed along the
outer circumferential face 41 of the conductor ring 40 with
substantially the same dimension as the outer diameter of the
conductor ring 40 from the open end 31. The outer circumferential
face of the cylindrical connection portion 34 is a smooth
arc-shaped surface, and allows the mounting of the later-described
swage ring 50 from the outside.
[0038] On the outer circumferential face 21A of the pipe 21, the
conductor ring 40 that is held so as to be parallel with the O-ring
22 is formed by bending a conductive metal plate made of aluminum,
an aluminum alloy, copper, a copper alloy, or the like into a
circular arc, and the overall shape of the conductor ring 40 is a
C-ring shape as shown in FIG. 4. The inner diameter of the
conductor ring 40 is somewhat larger than the outer diameter of the
pipe 21, and is set to a dimension that allows the conductor ring
40 to be inserted into the pipe 21 and be moved.
[0039] The conductor ring 40 has an outer circumferential face 41
as the face that faces the cylindrical connection portion 34 of the
tubular accordion member 30, and an inner circumferential face 42
as the face that faces the outer circumferential face 21A of the
pipe 21. Serrations 43 (corresponding to protrusion/recession
portions) are formed on the outer circumferential face 41 and the
inner circumferential face 42. The serrations 43 are formed by
performing so-called knurling work, and due to multiple grooves
forming a lattice being formed in a continuous manner, many
projections having a parallelogram shape are aligned along a
predetermined direction at a predetermined interval. Note that the
predetermined direction is a direction that obliquely crosses the
width direction of the conductor ring 40, that is to say, the axial
direction of the pipe 21.
[0040] The swage ring 50 that swages the cylindrical connection
portion 34 to the pipe 21 with the conductor ring 40 therebetween
is made of metal (e.g., an aluminum alloy, stainless steel, copper,
or a copper alloy), and is ring-shaped. The swage ring 50 is shaped
as a band plate that extends along the axial direction of the swage
ring 50, and the width dimension substantially conforms to the
width dimension of the conductor ring 40 and the cylindrical
connection portion 34 of the tubular accordion member 30. The inner
diameter of the swage ring 50 is larger than the outer diameter of
the pipe 21 before swaging.
[0041] The following describes an example of the process by which
the swage ring 50 is used to constrict the tubular accordion member
30 around the pipe 21 with the conductor ring 40 therebetween.
[0042] First, the conductor ring 40 is mounted on the pipe 21, and
then the O-ring 22 is fitted onto the pipe 21. The pipe 21, on
which the conductor ring 40 and the O-ring 22 are held, is then
inserted into the tubular accordion member 30, beginning with the
guiding inclined face 21C. The pipe 21 is pushed forward until the
O-ring 22 reaches a position where it is accommodated in the seal
tube portion 33 of the tubular accordion member 30, and when the
O-ring 22 forms a seal by being in close contact with the inner
circumferential face of the seal tube portion 33 and the outer
circumferential face 21A of the pipe 21, it is checked whether the
cylindrical connection portion 34 and the conductor ring 40 overlap
each other at the constricting position, and the swage ring 50 is
fit directly above the constricting position. At this time, the
positional relationship is such that the pipe 21, the conductor
ring 40, the cylindrical connection portion 34 of the tubular
accordion member 30, and the swage ring 50 are substantially
concentric in order from the axial center side.
[0043] The pipe 21, the conductor ring 40, the tubular accordion
member 30, and the swage ring 50 are set in a swage mold (not
shown) in this state. When the mold is clamped, the swage ring 50
is pressed toward the cylindrical connection portion 34 of the
tubular accordion member 30, and the cylindrical connection portion
34 is pressed against the conductor ring 40 so as to be embedded in
the serrations 43 formed on the outer circumferential face 43. The
diameter of the conductor ring 40 also decreases along the outer
circumferential face 21A of the pipe 21, and serrations 43 formed
on the inner circumferential face 42 that faces the outer
circumferential face 21A of the pipe 21 dig into the pipe 21. At
the same time, the surplus length portion of the swage ring 50
protrudes outward so as to form a pair of left and right ear
portions 51 as shown in FIG. 3. These ear portions 51 have a folded
back shape in which portions of the inner circumferential face of
the surplus length portion are in close contact with each other.
The portion other than the ear portions 51 has an overall
substantially circular shape according to which the outer
circumferential face 21A of the pipe 21, the conductor ring 40, and
the cylindrical connection portion 34 of the tubular accordion
member 30 are in close contact with each other, and of course the
portion of the swage ring 50 other than the ear portions 51 is in
close contact with the cylindrical connection portion 34 from the
outside. In this way, by swaging these portions from the outside
with the swage ring 50, the conductor ring 40 and the tubular
accordion member 30 are uniformly fastened to the pipe 21. At the
same time, the serrations 43 formed on the outer circumferential
face 41 and the inner circumferential face 42 of the conductor ring
40 dig into the outer circumferential face 21A of the pipe 21 and
the inner circumferential face of the cylindrical connection
portion 34 of the tubular accordion member 30, which they face.
Accordingly, the pipe 21 and the tubular accordion member 30 are
forcibly fixed to each other via the conductor ring 40, thus
securing connection reliability.
[0044] As described above, according to the present embodiment,
with the shield member 20 that encloses the electrical wires 11,
the metal tubular accordion member 30 is fit onto the metal pipe 21
via the metal conductor ring 40, and the pipe 21 and the tubular
accordion member 30 are connected due to be swaged from the outside
with the swage ring 50. Accordingly, it is possible to have
superior ease of arrangement work and improved shield performance
compared to the case of integrating braided wire such as a tubular
braided member as in conventional technology.
[0045] Specifically, since braided wire is formed by braiding thin
metal wires into a mesh, the thin metal wires easily become frayed,
especially at the ends of the braided wire. The frayed thin metal
wires easily become caught on a peripheral member during attachment
work and the like, and there is the risk of a reduction in
workability. Similarly, braided wire configured from thin metal
wires also easily rips, and there is the risk of a reduction in
shield performance if it rips.
[0046] In contrast, according to the present embodiment, instead of
braided wire, the tubular accordion member 30, which is formed into
a thin-foil according-like shape, is connected to the pipe 21, thus
preventing fraying at its ends and eliminating the risk of the
tubular accordion member 30 becoming caught on a peripheral member
during attachment work or the like. This makes it possible to have
superior ease of arrangement work.
[0047] Also, since the tubular accordion member 30 is foil-shaped
overall, it is sturdier and less easily ripped compared to braided
wire obtained by braiding thin metal wires. In other words, since
the tubular accordion member 30 has superior durability, it is
possible to reliably prevent interference between the inserted
electrical wires 11 and foreign objects, and protect them from
other peripheral members. Additionally, due to using the sturdy
tubular accordion member 30 that is not easily ripped, it is
possible to achieve shield performance compliant with the metal
pipe 21, thereby enabling an improvement in the overall shield
performance of the shield member 20. Also, since the main portion
32 of the tubular accordion member 30 has an accordion-like shape
due to alternatingly arranging the convex portions 32A and the
concave portions 32B, the tubular accordion member 30 can flexibly
follow the path along which the electrical wires 11 are to be
arranged.
[0048] Also, since the tubular accordion member 30 is constricted
via the conductor ring 40 held on the outer circumference of the
pipe 21, it is possible to improve the reliability of the
connection with the pipe 21 and the tubular accordion member 30.
Specifically, the serrations 43 are formed on the inner
circumferential face 42 of the conductor ring 40 that faces the
outer circumferential face 21A of the pipe 21, and on the outer
circumferential face 41 of the conductor ring 40 that faces the
cylindrical connection portion 34 of the tubular accordion member
30. Accordingly, even if an oxide layer is formed on the outer
circumferential face 21A of the pipe 21 or the inner
circumferential face of the tubular accordion member 30, the oxide
layer will be broken when pressed by the serrations 43, thus
establishing a favorable electrical connection state between the
pipe 21 and the tubular accordion member 30. This enables improving
the reliability of the connection with the pipe 21 and the tubular
accordion member 30, and improving shield performance.
[0049] More specifically, first, if serrations 43 configured by
multiple protrusion/recession portions are provided on the inner
circumferential face 42 of the conductor ring 40 that faces the
outer circumferential face 21A of the pipe 21, when the conductor
ring 40 is constricted from the outside by the swage ring 50, the
serrations 43 will dig into the pipe 21, and even if an oxide film
has formed on the outer surface of the pipe 21, the oxide film will
be broken, and the electrical connection state between the
conductor ring 40 and the pipe 21 will be favorable. Also, since
the serrations 43 are, similarly to the inner circumferential face,
also formed on the outer circumferential face 41 (outer surface) of
the conductor ring 40 that faces the inner circumferential face of
the tubular accordion member 30, when the conductor ring 40 is
constricted from the outside by the swage ring 50, the serrations
43 will dig into the inner circumferential face (inner surface) of
the tubular accordion member 30, and the electrical connection
state between the conductor ring 40 and the tubular accordion
member 30 will similarly be favorable. As a result, it is possible
to improve shield performance with respect to the electrical wires
11 inserted into the pipe 21.
[0050] Also, the serrations 43 formed on the conductor ring 40 can
be easily formed by knurling work. Also, since the serrations 43
are configured from multiple protrusions, when they dig into the
pipe 21 and the tubular accordion member 30, a greater surface area
of contact with the conductor ring 40 and the two members can be
secured, thus making it possible to suppress contact resistance and
further secure sufficient connection reliability.
[0051] Also, the serrations 43 are shaped such that the many
protrusions shaped as parallelograms are aligned along a
predetermined direction at a predetermined interval, and the
predetermined direction is a direction that obliquely crosses the
axial direction of the pipe 21, and therefore holding force for
holding the pipe 21 and the tubular accordion member 30 together
acts against the direction in which they attempt to separate (i.e.,
the axial direction of the pipe 21), thus making it possible to
more forcibly connect the pipe 21 and the tubular accordion member
30.
[0052] Also, in the case where an oxide layer is formed on the
surfaces of the pipe 21 and the tubular accordion member 30, if the
pipe 21 and the tubular accordion member 30 are simply connected
surface-to-surface using the swage ring 50, the pipe 21 and the
tubular accordion member 30 would be electrically connected via
that oxide layer, thus leading to the problem of a rise in contact
resistance. However, with the present embodiment, the serrations 43
of the conductor ring 40 can dig into the pipe 21 and the tubular
accordion member 30 and break through the oxide layers so as to
come into contact with the inner conductor, thus making it possible
to suppress contact resistance to a low level and sufficiently
secure the reliability of the connection with the pipe 21 and the
tubular accordion member 30. As described above, since the pipe 21
and the tubular accordion member 30 are swaged from the outside by
the swage ring 50 with the conductor ring 40 therebetween,
sufficient electrical connection can be obtained, thus enabling
improving shield performance with respect to the electrical wires
11 inserted in the pipe 21.
[0053] Also, since the conductor ring 40 is shaped as a C-ring, by
setting its dimension larger than the outer diameter of the pipe 21
so as to allow it to move relative to the pipe 21, even after the
conductor ring 40 is held on the pipe 21, the position of the
conductor ring 40 can be moved in conformity with the tubular
accordion member 30 and the swage ring 50, thus enabling achieving
superior ease of attachment work. Also, even if the inner diameter
dimension of the conductor ring 40 is set so as to be larger than
the outer diameter of the pipe 21 for the above reasons, the
conductor ring 40 can be fixed to the pipe 21 by reducing the
diameter in swaging, thus avoiding problems.
[0054] Also, since the cylindrical connection portion 34, which is
arranged on the conductor ring 40 and is swaged by the swage ring
50, has a shape that conforms to the outer circumferential face 41
of the conductor ring 40, workability is superior compared to the
case where, for example, the swage portion is also shaped as an
accordion similarly to the main portion 32. Specifically, when the
pipe 21 and the tubular accordion member 30 are constricted by the
swage ring 50 with the conductor ring 40 therebetween, if the
cylindrical connection portion 34 that directly comes into contact
with the conductor ring 40 is shaped as a cylinder that conforms to
the outer circumferential face 41 of the conductor ring 40, it is
possible to make it unlikely for the tubular accordion member 30 to
become displaced relative to the conductor ring 40 before and after
swaging. This enables more reliably constricting the tubular
accordion member 30 to the pipe 21 via the conductor ring 40, and
enables achieving superior workability. Also, since the swage
portion is shaped so as to conform to the outer circumferential
face 41 of the conductor ring 40, a larger surface area of contact
between the conductor ring 40 and the tubular accordion member 30
is secured, thus enabling suppressing contact resistance to a low
level and achieving sufficient electrical connection.
[0055] Also, out of the portion where the pipe 21 and the tubular
accordion member 30 overlap each other, the O-ring 22 is fitted
onto the end portion of the pipe 21 arranged more toward the main
portion 32 side of the tubular accordion member 30 than the
cylindrical connection portion 34, which is the swage portion, is.
For close contact with the O-ring 22, the tubular accordion member
30 is provided with the seal tube portion 33 whose diameter expands
with a step from the cylindrical connection portion 34.
Accordingly, the O-ring 22 forms a water-tight seal between the
outer circumferential face 21A of the pipe 21 and the seal tube
portion 33, thus making it possible to prevent the intrusion of
water, entrance of foreign objects, and the like from the outside
via gaps or the like between the cylindrical connection portion 34,
which is swaged by the swage ring 50, and the conductor ring 40 or
the outer circumferential face 21A of the pipe 21.
[0056] Although Embodiment 1 of the present invention has been
described above, the present invention is not limited to the above
embodiment, and can also include variations such as the following.
Note that in the following variation, members similar to those of
the above embodiment will be denoted by the same reference signs as
in the above embodiment, and descriptions thereof will not be
given.
Variation 1 of Embodiment 1
[0057] The following describes Variation 1 of Embodiment 1 with
reference to FIG. 5. The present variation differs from Embodiment
1 in that multiple slits 63 are formed in a tubular accordion
member 60.
[0058] Multiple (four in the present embodiment) slits 63 are cut
into a cylindrical connection portion 61 of the tubular accordion
member 60, beginning at an open end 62 and extending in the
lengthwise direction of the cylindrical connection portion 61
(tubular accordion member 30). These slits 63 are formed in the
cylindrical connection portion 61 at equal intervals in the
circumferential direction of the open end 62. The length dimension
of the slits 63 in the lengthwise direction of the cylindrical
connection portion 34 is set such that the slits 63 begin at the
open end 62, completely pass through the cylindrical connection
portion 34, and reach a position before the increase in diameter
toward the seal tube portion 33.
[0059] Compared with the case of not providing the slits 63 as in
Embodiment 1, according to this configuration, it is possible to
more easily reduce the diameter of the tubular accordion member 60
in conformity with the outer diameter of the pipe 21 when swaging
it from the outside with the swage ring 50, thus enabling achieving
superior ease of attachment work.
[0060] Also, providing the slits 63 in the cylindrical connection
portion 61 enables achieving a configuration in which connection to
the outer circumferential face 21A of the pipe 21 is easy. As a
result, it is easy to secure the surface area of contact, and it is
possible to suppress contact resistance and secure sufficient
connection reliability. Even with this variation, it is possible to
achieve more superior shield performance for the shield member 65
configured from the pipe 21 and the tubular accordion member
60.
Embodiment 2
[0061] The following describes Embodiment 2 of the present
invention with reference to FIG. 6.
[0062] The present embodiment differs from Embodiment 1 with
respect to the shape of serrations 73 of a conductor ring 70. Other
configurations are similar to those in Embodiment 1, and
descriptions thereof will not be given.
[0063] The serrations 73 are formed by alternatingly arranging a
convex portion 73A and a concave portion 73B, which extend along
the axial direction of the pipe 21, on an inner circumferential
face 71 and an outer circumferential face 72 of the conductor ring
70.
[0064] According to this configuration, similarly to Embodiment 1,
the serrations 73 dig into the pipe 21 and the tubular accordion
member 30, thus forcibly fixing them to the conductor ring 70,
thereby making it possible to secure the reliability of the
connection between the pipe 21 and the tubular accordion member 30.
Forcibly connecting the pipe 21 and the tubular accordion member 30
also enables improving shield performance with respect to the
electrical wire 11 inserted therein.
Embodiment 3
[0065] The following describes Embodiment 3 of the present
invention with reference to FIG. 7.
[0066] The present embodiment differs from Embodiment 1 and
Embodiment 2 with respect to the shape of serrations 83 of a
conductor ring 80. Other configurations are similar to those in
Embodiment 1 and Embodiment 2, and descriptions thereof will not be
given.
[0067] The serrations 83 are formed by alternatingly arranging a
convex portion 83A and a concave portion 83B, which extend along
the circumferential direction of the conductor ring 80, on an inner
circumferential face 81 and an outer circumferential face 82 of the
conductor ring 80, thus giving the serrations 83 the shape of
protrusions and recessions.
[0068] According to this configuration, similarly to Embodiment 1
and Embodiment 2, the serrations 83 dig into the pipe 21 and the
tubular accordion member 30, thus forcibly fixing them to the
conductor ring 80, thereby making it possible to secure the
reliability of the connection between the pipe 21 and the tubular
accordion member 30. Forcibly connecting the pipe 21 and the
tubular accordion member 30 also enables improving shield
performance with respect to the electrical wire 11 inserted
therein.
Other Embodiments
[0069] The present invention is not limited to the embodiments
described by way of the above descriptions and figures, and
embodiments such as the following are also encompassed in the
technical scope of the present invention.
[0070] (1) Although the conductor rings 40, 70, and 80 in the
above-described embodiments are shaped as C-rings, there is no
limitation to this. A configuration is possible in which, for
example, the conductor ring is fitted around the pipe before the
tubular accordion member is swaged with the swage ring. According
to this configuration, the pre-fixed conductor ring does not become
misaligned when the tubular accordion member is swaged with the
swage ring.
[0071] (2) Although the serrations 43, 73, and 83 are formed over
substantially the entirety of the inner and outer circumferential
faces of the conductor rings 40, 70, and 80 in the above-described
embodiments, there is no limitation to this. They may be partially
formed in only a portion that comes into contact with the pipe 21
and the tubular accordion member 30 or 60.
[0072] (3) Although the serrations 43 are formed by performing
knurling work in Embodiment 1, there is no limitation to this. Any
mode may be used as long as the shape of protrusions and recessions
is achieved. For example, the protrusion/recession portions may be
configured by forming curved grooves, recession portions whose
outer shape is a polygon such as a triangle or a quadrangle, or
recession portions whose outer shape is circular or oblong, for
example.
[0073] (4) Although there are two or three electrical wires 11 in
the above-described embodiments, there is no limitation to this.
The number of electrical wires 11 may be one, or four or more.
[0074] (5) Although the cross-sectional shape of the pipe 21 is a
true circle in the above-described embodiments, there is no
limitation to this. The shape may be changed to a flattened shape
such as an ellipse depending on the arrangement situation.
[0075] (6) Although the swage portion such as the outer
circumferential face 21A of the pipe 21 and the cylindrical
connection portion 34 of the tubular accordion member 30 are not
subjected to plating processing or the like for the purpose of
preventing rusting and electrical corrosion in the above-described
embodiments, there is no limitation to this. Rust prevention may be
achieved by performing zinc plating on end portions of the pipe 21.
Also, electrical corrosion occurring due to contact with different
types of metal may be suppressed by performing tin plating on
portions of the face of the tubular accordion member 30 that come
into contact with the pipe 21.
[0076] (7) Although the pipe 21 is made of a metal such as aluminum
or an aluminum alloy, and the tubular accordion member 30 is made
of a metal such as copper or a copper alloy, which are superior in
terms of flexibility, in the above-described embodiments, there is
no limitation to this. They may be configured by another metal
material or a conductive material other than metal.
[0077] (8) Although the pipe 21 and the tubular accordion member 30
are conductively connected by swaging with the ring-shaped swage
ring 50 in the above-described embodiments, there is no limitation
to this. Swaging may be performed using a C-shaped swage ring, for
example. Also, a mode is possible in which the pipe and tubular
accordion member are constricted from the outside using a
constricting member such as a tie band.
REFERENCE SIGNS LIST
[0078] 10 Shield conductor [0079] 11 Electrical wire [0080] 20
Shield member [0081] 21 Pipe [0082] 22 O-ring (seal ring) [0083] 30
Tubular accordion member [0084] 31 Open end [0085] 32 Main portion
[0086] 32A Convex portion [0087] 32B Concave portion [0088] 33 Seal
tube portion [0089] 34 Cylindrical connection portion [0090] 40
Conductor ring [0091] 41 Outer circumferential face [0092] 42 Inner
circumferential face [0093] 43 Serrations (protrusion/recession
portions) [0094] 50 Swage ring (constricting member)
* * * * *